A systematic review of the effects of impaired glucose tolerance (IGT) on the incidence of chronic kidney disease (CKD) in young adults

Abstract

Objective: The risk of chronic kidney disease (CKD) is elevated in patients with diabetes mellitus but the effect of impaired glucose tolerance (IGT) is not known. This systematic review investigates the risk of CKD associated with IGT in young adults aged 18–40 years. Methods: CINAHL, EMBASE, MEDLINE, PubMed, Cochrane libraries and grey literature were searched from inception to January 2015 without language restriction for case-control and cohort studies comparing the frequency of CKD in cases aged 18–40 years with IGT/IFG (impaired fasting glucose) with controls without glycaemic abnormality or with type 2 diabetes (T2DM). CKD outcomes were determined by: estimated glomerular filtration rate, albumin creatinine ratio, proteinuria ≥1, serum creatinine, protein creatinine ratio and creatinine clearance levels. Results: Initial searches identified 90 citations potentially meeting the inclusion criteria. After full text review, 19 cohort studies and no case-control studies met the inclusion criteria, but only one cohort study reported separate data for persons aged 18–40 years. This study only compared the incidence of CKD in individuals with IGT with those with T2DM. The annual incidence of CKD was 0.13% per person-year compared with 2.4% in patients with T2DM. Conclusion: The results of this systematic review demonstrate that the risk of CKD in young adults with IGT/IFG is lacking. Further research is needed to estimate the incidence of CKD in this cohort of individuals. To bridge this gap in evidence, large epidemiological databases may be examined to quantify the risk of CKD in young adults aged 18–40 years with IGT/IFG compared with those with normoglycaemia. Data from these databases may potentially inform a prognostic study which may be useful in understanding the course and factors associated with CKD development. Finally, the results may emphasise the importance of identifying individuals with IGT/IFG earlier and implementing interventions to prevent or delay the development of CKD.